1. Field of the Invention
The present invention relates to an endoscope system that picks up an image in a subject by image pickup means.
2. Description of the Related Art
In recent years, an endoscope having an insertion portion capable of being inserted into a body cavity or the like has been widely used in a medical field and other fields.
Meanwhile, in a case of performing insertion into a luminal organ which is branched complicatedly such as bronchia in a body cavity and examining (an affected tissue of) a target region on a distal end side of a luminal organ, or performing biopsy and treatment by a treatment instrument, there is a case where it is difficult to introduce a distal end of an insertion portion to a vicinity of the target region only by an endoscopic image which is obtained when performing the insertion.
Therefore, there is proposed a system or an apparatus which performs display, etc. for supporting an operation of introducing the distal end of the insertion portion of the endoscope to the vicinity of the target region.
For example, in Japanese Patent Laid-Open Publication No. 2002-200030 as a first conventional example, since it has been difficult to acquire a three-dimensional image by imaging distal bronchia, there is disclosed an apparatus provided with map image synthesizing means that performs registration between a coordinate system of three-dimensional image data of the bronchia and a position of the distal end of the insertion portion, thereafter sequentially stores positions of the distal end of the insertion portion, and synthesizes a locus image on the three-dimensional image data of the bronchia.
Further, in Japanese Patent Laid-Open Publication No. 2004-89483 as a second conventional example, since a diameter of a route to reach a location of an affected part as a target in the bronchia is not known, there is disclosed an apparatus in which, when selecting a bronchia endoscope having an optimal diameter, an insertion route is set in the three-dimensional image of the bronchia, an inner bronchial diameter at a predetermined position in the set insertion route is calculated, and an insertion limit position is calculated from the calculated inner diameter of the bronchia and an insertion diameter of the bronchia endoscope.
Furthermore, in Japanese Patent Laid-Open Publication No. 2009-56238 as a third conventional example, in order to improve precision of image matching between an endoscopic image as an observation image obtained by an endoscope and a virtual endoscopic image generated based on image data in a three-dimensional region of the bronchia, there are disclosed image synthesizing means that displays the virtual endoscopic image, an virtual endoscopic schematic image or the like to be superimposed on the endoscopic image, and image correction means that makes directions of the images coincide with each other.